Automatic steering device for ships



Oct. 4, 1938. F. s. HODGMAN AUTOMATIC STEERING DEVICE FOR SHIPS OriginalFiled Sept. 19, 1934 4 Sheets-Sheet l mm J9EE". mot: 2%

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AUTOMATIC STEERING DEVICE FOR SHIPS Original Filed Sept. 19. 1934 4Shets-Sheet 3 Hi5 ATTORNEY.

Oct. 4, 1938. F. s. HODGMAN AUTOMATIC STEERING DEVICE FOR SHIPS OriginalFiled Sept. 19, 1934 4 Sheets-Sheet 4 a. I I

Patented Oct. 4, 1938 UNITED STATES PATENT OFFICE AUTOMATIC STEERINGDEVICE FOR SHIPS Application September 19, 1934, Serial No. 744,628Renewed February 25, 1938 9 Claims.

This invention relates to improvements in automatic steering devices forships, wherein the main course controller is automatically maintainedsynchronous with the gyro compass and wherein a predetermined coursechange may be ordered and set on the course indicator dial and the shipwill automatically come around to the new course without furthermanipulation by the pilot. It is understood, of course, that I use theword ships" throughout the specification in the generic sense and intendto include thereby both water borne and air borne vehicles, that is,both vessels and dirigible aircraft. A further object of the inventionis to improve the controller arrangement so that more sensitive controlis obtained. A further object of the invention is to provide a means forlimiting at will the amount of rudder throw regardless of the totalamount of course change desired. In other words, if a group of vesselsis steaming in formation, it may be desired to change course through anydesired angle, such as but for the individual ships to swing around anarc of predetermined radius in doing so. With the ordinary automaticsteering device the rudder would be run hard over in order to make sucha large course change and the ship would turn to the new course about ashort radius arc. I have provided, according to my invention, means sothat the rudder may be limited to any desired angle in making a turnthrough the automatic steering device.

Referring to the drawings,

Fig. 1 is a diagrammatic view, in perspective, of the elements of myimproved automatic steering device.

Fig. 2 is a diagrammatic view, in skeleton form, of the same.

Fig. 3 is a vertical section through the top portion of the steeringstand.

Fig. 4 is a plan view of the indicator dial on the stand.

Fig. 5 is a detail sectional plan view of the contact on the mastercontroller, the section being taken on line 55 of Fig. 3.

Fig. 6 is a sectional view through the auxiliary controller, and Fig. 7is a wiring diagram of a slightly modified form.

This invention is an improvement, in many respects, on the type ofautomatic steering system shown in my prior Patent No. 2,015,183, datedSeptember 24, 1935, for Self-synchronous automatic pilots, and in myprior Patent No. 1,965,378 of July 3, 1934, for Sensitive remote controlsystem and automatic pilot, and to that extent is a continuation of thesame.

Referring first to the Figs. 1, 2 and 3, my automatic steering device isshown as controlled from a gyro or other compass (not shown) through arepeater motor 35, the transmitter for which is geared to rotate manytimes for one turn of the ship. Said motor operates an auxiliarycontroller 36, shown in the form of trolleys which contact withreversing contact rings 31 and 31'. Said contacts control a smallreversible motor 21 which operates the main controller contacts l5. Asshown in Fig. 2, the motor 21 drives a gear 28 on shaft 39'. One end ofsaid shaft is shown as having a pinion 29 which turns a large gear 30,furnishing a follow-back connection to the controller 36. This gear isshown as having a large hub 3| (Fig. 6) on which is keyed a sleeve 4|]having annular teeth 4|, by means of which said sleeve may be axiallymoved along said hub, by means of a pinion 43 on shaft 44 which mesheswith said teeth 4|. By turning said shaft, the sleeve may be moved alongsaid hub for the telemotor lost motion adjustment. To this end thesleeve is provided with a triangular slot 45, into which projects a pin46 on an interior sleeve 41. Said sleeve has secured thereto a contactcarriage 48 which supports the reversing contacts 31, 31'. It willreadily be seen that by adjusting the sleeve 40 axially, the amount oflost motion between the pin 46 and the walls of the slot 45 may beadjusted to vary the telemotor adjustment. The trolleys 20' and 20" arecarried by a central shaft 2| actuated by repeater motor 35, eitherdirectly as in Fig. 2 or indirectly as in Figs. 3 and 6, through gears33 and 33. Slip rings 23, spring arm 80, and brushes 23 and 23" areshown on the outer surface of carriage 48 for leading current out of thesplit rings 31 and 31'.

A hand lever 24 mounted on shaft 24 controls a clutch which couples anduncouples shafts 39 and 39, and hence the servo motor 21, from the maincontacts I5. When said handle is in the position marked gyro, clutchfaces 25, 26 are closed and the motor 21 turns said contacts throughshafts 39 and 39', differential 20, worm i9, worm wheel l8 and shaft 38,the clutch being held closed by the spring 22. When, however, the handleis thrown to the hand position, the clutch is open and all mechanicalcontrol from the gyro compass is disconnected. At this time the compassside of the differential 20 may be prevented from rotating by aplurality of pins 50 on spring housing 22' which engage pin 5| on clutch26 (see Figs. 2 and 3).

The master controller in this instance is shown as contact arm 55 andopposite contacts 56, 51, which arm is operated from a cam device onshaft 38 (Figs. 3 and 5) having camming surfaces l6. Secured to sleeve 8adjacent said cam device is a member 53 on which is pivotally mounted arocker arm 54 having rollers I8, I8 thereon adapted to be engaged by oneor the other of the cam surfaces on said cams 16. In the position shownin Fig. 5, the spring arm 55 secured to said rocker arm lies midwaybetween contacts 56 and 51 on member 53, but a very slight movement ofthe cam in one direction or the other will close one or the other ofsaid contacts, not only because of the shape of the cam but because thecontact arm 55 is much longer than the radius of cam I6 or the radius ofrocker arm 54. By this means, coupled with the auxiliary motor control,very quick action of the main steering engine is secured with veryslight lost motion.

The follow-up from the steering control motor I to the controller may beof any suitable type, mechanical or electrical. As shown in Fig. 2,suitable gearing 3, 4 and 5 is provided for this purpose, which may alsoserve to actually turn the rudder or rudder control from the mainsteering wheel |'I' (Fig. 1) or from the wheel I'I (Fig. 2), which inthis figure performs either the function of the gyro-pilot trick wheelor the main pilot wheel by pushing it back or forward to engage eitherclutch face 5 on sleeve I on which bevel gear 5' is mounted, or clutchface 6 on shaft I| connected by sprocket I8 to large sprocket II ondifferential 28. Sleeve I is shown as turning a worm wheel 4| throughworm I4 and gears 8. Worm wheel 4| is secured to a sleeve 8 whichcarries the member 53 of contactor l5. Shaft 38 extends through saidsleeve and may carry at the top thereof 'an indicator 68 showing thecourse which has been set with respect to the compass points, which maybe marked on the card 6|. Said card is shown as secured to a large gear62 which is frictionally mounted on the hub of the worm wheel 63,friction contact being provided by spring 64. Said card will thereforenormally rotate with said worm wheel, but may be set with respectthereto by pushing in on the handle 65, thus bringing the crown gear 66into mesh with said gear 62. The worm wheel 63 is shown as actuated froma worm 61 on the shaft 68 of a sprocket 69. The chain 69 coupled withsaid sprocket is shown as leading both to the sprocket I8 on the shaftII of the course changing wheel l1 and also to a sprocket connected tothe planetary arm of a differential 28. The card 6| therefore, when readin connection with the index 68 which is shown in the shape of a shipshull, will show continuously the ship's compass heading as long asautomatic steering is used, even including the short time that thecourse is being changed, at which time it may be used for setting in thedesired course change, since the scale on card 6| may be read not onlyon the index 68 but also on the fixed lubbers line I2.

When steering by hand (i. e., through trick wheel I'I), index member 68will show wheel position. To this end, the index member 68 also has anindex I6 at the rear representing wheel position, and sleeve 8 may alsohave an indicator secured thereto in the form of a graduated segmentalcard I5, having a zero index 11'. By comparing I6 and II the rudderfollow-up may be observed and by reading I6 on scale 11 the amount ofturn of the wheel is indicated. A mask I8 is cut out adjacent said scaleindices to show the index I6 at the rear end of the index 88. Scale 11and index 11' may also be read with reference to the lubbers mark I8 onmask I8 to show rudder position.

In order to limit the rudder throw for the purpose above described, Ishow in Fig. 1 an on and-off rudder control handle. 88, shown as mountedon a shaft 8| which is both rotatably and slidably mounted. When saidshaft is in the forward position under the influence of the spring 82,the contacts 83 and 84 are bridged and contacts 85 and open. In thisposition the circuit to the master gyro pilot controller I5 is open andthe contacts beneath the handle 88 are energized. Therefore, when thehandle 88 is rotated to the right, for instance, the contacts 81, 81 arebridged and the power motor I actuated to drive the rudder in the properdirection. Opposite movement of the handle will have the reverseoperation by closing contacts 89, 88'. When, however, the handle 88 ispushed to the rear, the contacts 85 and 86 are bridged, thus placing themaster controller contacts in the control of the power motor.

In using this portion of my invention, let us suppose that the ship isbeing steered automatically and the pilot desires to change course inother words, to steer due east instead of due north, as indicated inFig. 1. The pilot first rotates the trick wheel II until 90 registerswith the lubbers mark I2. Simultaneously the ship's index 68 will turncounterclockwise 90 and the rudder will start to move to starboard. Therudder will continue to move to starboard, unless interrupted, until itreaches its hard over position, but if the pilot desires to turn at agiven rate, he pulls out the handle 88 when the rudder indicator 'IIregisters the desired angle, say 15, on the index I8. This willinterrupt the circuit to the power motor. When the ship has aboutreached the course, the pilot may again push in the handle 88 or he mayturn the handle 88, before pushing in, to steady the ship on its courseby hand, and only push the handle in after the ship has been brought tothe new course, as indicated by the ship's pointer 68 registering withthe 90 mark on the compass dial 6|.

In steering by hand (with the lever 24 in the hand position), the card6| no longer represents the compass course which has been set and theindex I6 may then be used as a wheel position index, cooperating withthe rudder index 11' to show whether the rudder is following the wheel.

Referring now to Fig. '7, there is here illustrated a wiring diagramshowing a slightly modified form of the invention in which the camcontactor I6 is replaced by an escapement form of contactor and in whichan electric follow-back means is employed from the rudder instead ofmechanical shafts. The auxiliary motor 21 and contactor 36 may be thesame as shown in the other figures. The preferred construction ofcontactor is to have the angular position of rings 31 and 31 slightlydisplaced. By this means, together with a special winding on the motor21, a very quick stoppage of the motor armature is secured, as follows:

The motor 21 is shown as provided with a continuously excited fieldwinding 98 and the armature is connected directly across the collectorbrushes 23, 23" which bear on collector rings 23 (not shown in Fig. 7)With the trolleys and contacts in the position shown in Fig. 7, thecurrent will tend to flow from the plus side of the line through trolley28", brush 23", armature 75 21 from right to left, and one side R of midtapped or Wheatstone bridge type resistances R, R to the minus side ofthe line. However, current would also tend to flow from the plus side ofthe line through trolley 20', brush 23, through the armature 21 fromleft to right, and through equal resistance R to the minus side of theline. Therefore no line current would flow through the armature.However, it should be observed there is a direct short circuit throughthe armature and resistances R, R, and also from the armature throughbrush 23", trolley 20", trolley 20', brush 23' and back to the otherside of the armature. Therefore the armature will be very quicklybrought to rest by dynamic braking. In fact, with the small motoremployed for driving this contactor, the armature has been brought torest from a speed of several thousand revolutions within one revolutionof the armature. By this arrangement, also, the eifective dead space maybe adjusted by varying the relative angular position of the two rings31, 31'. The application of this special motor circuit to broader fieldsthan electric steering gear for ships is reserved for my continuationapplication Serial No. 132,713, filed March 24, 1937, for Positionalcontrol motors.

The motor 21 operates the contactor as before. In this instance thecontactor is shown as comprising a disc l6 carrying a single tooth 9|which normally engages a single notch in a rocker arm 92, pivoted at 93and thus constituting a Geneva movement. Said arm carries a pair ofspring contacts 9!, 94 adapted to contact with fixed contacts 56, 51'upon a slight revolution of the tooth 9| in one direction or the other.Further revolution of the disc I6 in the same direction merely holds thecontacts closed until the disc I6 is brought back to its originalposition or until the large disc 53', on which the pivot 93 is mounted,is revolved in the same direction to restore the original relativepositions of the tooth 9| and rocker arm 92.

Disc I6 is shown as mounted on a shaft 38, corresponding to the shaft 38in Figs. 2 and 3, which is shown as carrying a. ship's heading indicatoror reference mark 60' at the top thereof, corresponding to the ship'sheading indicator 60 in Fig. 4. A compass card 6| is also shown, as inFigs. 2 and 3. A follow-up worm wheel 4| is shown as operated indirectlyfrom a self-synchronous repeater motor 96, operated from aselfsynchronous sending generator 91 at the rudder. Said motor, being ofsmall power, is shown as turning the gear 4| by means of an electricalpower multiplying or follow-up system comprising a contactor 9B whichmay be similar to contactor 36, which controls the follow-up motor 21,similar to the motor 21. Motor 21' is shown as turning worm wheel ll onthe shaft of which is disc 53. The Geneva contactor shown in Fig. 7 hasthe advantage that it is self-synchronous throughout 360, and through itlarge course changes may be performed without destroying the synchronismbetween the compass and the controller.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle and operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention can be carried out by other means.Also, while it is designed to use the various features and elements inthe combination and relations described, some of these may be alteredand others omitted without interfering with the more general resultsoutlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure byLetters Patent is:

1. In an automatic electric steering gear for ships, a compass governedfollow-up controller, means for setting in any desired change in course,a non-follow-up or off and on controller, and a switch on the latter andoperable thereby for transferring the rudder control motor from theformer to the latter controller for limiting the rudder throw.

2. In an automatic steering gear for ships, an electric controllercomprising a rotatable cam member, a pair of contacts one or the otherof which is adapted to be closed by slight movement of the cam in eitherdirection, a rotatable member supporting said contacts, a motor actuatedby said contacts, compass controlled means for turning one of saidmembers, and follow up means from said motor for turning the other ofsaid members.

3. In an automatic steering gear for ships, a compass actuatedcontroller, a small power motor actuated therefrom, a rotatable cammember, a pair of contacts one or the other of which is adapted to beclosed by slight movement of the cam in either direction, a rotatablemember supporting said contacts, and rudder follow-up means for turningone of said members, the other member being differentially turned fromsaid motor.

4. In an automatic steering gear for ships, a compass actuatedcontroller, a small power motor actuated therefrom, a cam member, apivoted contact arm, one part of which is adapted to be moved by saidcam, the other part being further from the pivot than said cam andadapted to carry a contact, the cam being so shaped that slight movementthereof closes said contact and further movement leaves it unchanged,said motor operating to turn said member.

5. In an automatic steering gear, a compass actuated controller,comprising two pairs of semicircular rings each spaced from the other,a. relatively rotatable contact for each pair, the two pairs beingslightly displaced with respect to their contacts, and a reversiblemotor controlled from said contacts, having a continuously excited fieldand the armature connected across said contacts whereby the armature isdynamically braked when said contacts lie on opposing contacts of eachpair.

6. In an electrical steering gear for ships, 3. motor having field andarmature windings the former of which is of the continuously excitedtype, resistances of the Wheatstone bridge type across the armature andto one side of the supply, a steering controller device adapted to sendcurrent from the other side of said supply through said armature in oneor the other direction and through one or the other half of saidresistance, said controller in its mid or standstill position completinga short circuit around said armature to brake the motor dynamically.

7. In an automatic electric steering gear for ships, a rudder motor, acompass governed controller for said motor, and means for effecting achange of course, including a manually operable electric controller forsaid motor of the push button hard-over type and switching means on saidcontroller for transferring the rudder control from said compassgoverned controller to said manual controller, the length of time saidmanual controller is hard-over serving to determine the degree of rudderthrow, whereby the rate or turn of the ship to the new course may belimited to any desired rate.

8. In a steering gear for ships, a differential gear train, a steeringwheel connected to one arm of said differential, a servo motor forturning the rudder, and a controller for said servo motor actuated fromanother arm of said diflerential and comprising a rocker arm and acam-like device turning said rocker arm one way or the other for smallrelative displacement of said device, acting to drive said servo motorone way or the other until said device returns said arm to neutral, saidservo motor having a follow back connection to the third arm of saiddifferential.

9. In a steering gear for ships, a controller comprising a rotatable cammember, a three-position rocker arm which is thrown to one or the otherof its outer positions by lesser movement of the cam in eitherdirection, a rotatable member supporting said rocker arm, a servo motoractuated by said controller, steering control means for turning one ofsaid members, and follow-up means from said servo motor for turning theother of said members.

FREDERICK S. HODGMAN.

